CHIP-SCALE TESTING LABORATORY
The TOAN testbed facility has recently expanded its photonic devices testing facility into a dedicated lab: the CIAN Chip-Scale Testing Laboratory (CST). The CST has the capability to characterize unpackaged passive and active photonic chips and is directly connected to TOAN testbed through single-mode fiber and gigabit-Ethernet. This connectivity enables the insertion and evaluation of the unpackaged photonic chips on the network as a system. Pictures of the CST laboratory and a list of its capabilities are described below.
The CST facility supports characterization of passive waveguide devices as well as active devices such as lasers, modulators, transmitters and receivers. Optical signals can be coupled on and off chip via lensed fibers, butt coupling, or other specialized means. Passive device characterization can be performed through all fiber-optic telecommunication bands. Active characterization includes S-parameter testing up to 67GHz, and BER and eye-diagram testing up to 32Gb/s.
For system-level testing, packet streams up to 40Gb/s can be flowed through the device, and the network’s ability to process the return streams with suitable latency, bit rates, and in accordance with the modulation schemes being run, can be evaluated. Continue reading
A team of students from the University of Arizona, Columbia University, the University of California, Los Angeles, the University of Southern California, and Cornell University completed a test bed insertion and demonstration of the CIAN Box in the TOAN test bed during the May NSF site review. The configuration is shown schematically in Figure 1.
Figure 1. Credit: CIAN Box Team. Schematic of CIAN Box test bed insertion and associated networking architecture. DE = Distance Emulation, CDC = Colorless, Directionless, Contentionless, WSS = Wavelength Selectable Switch, DLI = Delay Line Interferometer, OSNR = Optical Signal-to-Noise Ratio, TiSER = Time Stretched Enhanced Recorder – used for quality of service measurement, OFDM = Orthogonal Frequency-Division Multiplexing, DP-QPSK = Dual-Polarization Quadrature Phase Shift Keying, OOK = On/Off Keyed
The distance emulators are designed to implement a variety of network impairments as shown in Figure 2. Various impairments, singly and in combination, were added to the signals and the quality of service (QOS) was monitored. If the QOS fell below the desired level, the signal was switched onto a different channel with a potentially different encoding scheme. After many late nights and long weekends the assembled system is shown in Figure 3. A picture of the implementation team is shown in Figure 4. Additional information can be found on the CIAN website.
Figure 2. Credit: CIAN Box Team. Description of the different impairments that can be added to the system. SMF = Single Mode Fiber, DCF = Dispersion-Compensating Fiber, PM = Polarization Maintaining, PDL = Polarization Dependent Loss, EDFA = Erbium Doped Fiber Amplifier, ROADM = Re-configurable Optical Add/Drop Multiplexer, SPM = Self Phase Modulation.
Figure 3. CIAN Box Test Bed insertion